Use enum from another class?

[Mutant_Fruit]

What error are you getting? I assume you just coded your method incorrectly and it's throwing an error saying you can't convert from enum to int? Your method signature should look like this:

void SetContainerType(class1.ContainterTypes container)
{
    if(container == class1.ContainerTypes.CT_XML)
        ConvertToXml();
}

I also wouldn't recommend casting your enums to and from their values for internal code, for example this is bad:

// This is bad
switch((int) myEnum)
{
     case 0:
        break;

    case 1:
        break;

    case 2:
        break;
}


// This is good
switch(myEnum)
{
     case MyEnum.Red:
        break;

    case MyEnum.Blue:
        break;

    case MyEnum.Green:
        break;
}